PDR Tool Accessory - RAC-3 Work on one or two knees. Easy control, movement & balance. Adjustable seat - Instead of sitting back on heels, fully adjustable seat provides upper body support,leaves feet free to control your movement. Kneepads - Comfortable, attached floating-like kneepads allow knees to rest & move freely. Eliminates direct knee to floor pressure, circulation problems, & allows you to work in shorts without having to wear kneepads with straps. 3" Casters - Allows you to roll to move, instead of crawling & bouncing on your knees. Elevates your body to eliminate normal pressure on toes, ankles & knees. Allows you to work over dirty, wet, or dusty areas easier & cleaner.Tool Tray - A feature really appreciated by all using the Racatac. They love having a place to keep their necessities right there rolling with them.